python3 compatibility: use relative imports

Use relative imports when using module's own modules - this makes a
clear distinction between already developed copy and installed package.

osc/util/archquery.py

@@ -1,7 +1,7 @@
 import os.path
 import re
 import tarfile
-import packagequery
+from . import packagequery
 import subprocess
 
 class ArchError(packagequery.PackageError):

osc/util/debquery.py

@@ -1,8 +1,8 @@
-import ar
+from . import ar
 import os.path
 import re
 import tarfile
-import packagequery
+from . import packagequery
 
 class DebError(packagequery.PackageError):
     pass

osc/util/packagequery.py

@@ -91,18 +91,18 @@ class PackageQuery:
         extra_tags = ()
         pkgquery = None
         if magic[:4] == '\xed\xab\xee\xdb':
-            import rpmquery
+            from . import rpmquery
             pkgquery = rpmquery.RpmQuery(f)
             extra_tags = extra_rpmtags
         elif magic == '!<arch>':
-            import debquery
+            from . import debquery
             pkgquery = debquery.DebQuery(f)
             extra_tags = extra_debtags
         elif magic[:5] == '<?xml':
             f.close()
             return None
         elif magic[:5] == '\375\067zXZ' or magic[:2] == '\037\213':
-            import archquery
+            from . import archquery
             pkgquery = archquery.ArchQuery(f)
         else:
             raise PackageError(filename, 'unsupported package type. magic: \'%s\'' % magic)

osc/util/rpmquery.py

@@ -1,7 +1,7 @@
 import os
 import re
 import struct
-import packagequery
+from . import packagequery
 
 class RpmError(packagequery.PackageError):
     pass